Prospective assessment of breakthrough infections and neurotoxicity and their association with cefepime trough concentrations in patients with febrile neutropenia.

Cefepime is a first-line antibiotic for the treatment of febrile neutropenia (FN) in haematological cancer patients. Therapeutic drug monitoring (TDM) of cefepime is frequently advocated. However, it remains unclear what range of concentrations should be targeted for maximal efficacy and minimal toxicity. Therefore, we examined the relationship between cefepime exposure and clinical efficacy or neurotoxicity in FN patients. This prospective, observational, single-centre study included all adult hospitalised patients presenting with FN at the haematology ward and treated with cefepime from August 2019 until October 2020. Primary outcomes were incidence of breakthrough infection and neurotoxicity and their relationship with free cefepime serum trough concentrations. A total of 76 patients were included, contributing 96 cefepime treatment courses. The median (interquartile range) estimated glomerular filtration rate according to the Chronic Kidney Disease Epidemiology Collaboration equation (eGFRCKD-EPI) and free cefepime trough concentration were 101 (85-112) mL/min/1.73m2 and 8.6 (4.9-16.2) mg/L, respectively. Interpatient and intrapatient variability in cefepime trough concentrations was largely explained by renal function. No cefepime-related breakthrough infections occurred during cefepime treatment. Neurotoxicity, probably induced by cefepime administration, occurred during 6/96 (6.3%) treatment courses. Patients with neurotoxicity showed a significant trend for higher trough concentrations (median 15.4 mg/L vs. 8.6 mg/L; P < 0.001). This study provides real-world clinical data showing that high cefepime dosage is efficacious and safe in FN patients. Routine TDM does not appear to be needed in FN patients with preserved renal function. However, TDM might be reserved for FN patients at high risk of cefepime-induced neurotoxicity or when intended to cover pathogens with a minimum inhibitory concentration >1 mg/L.

A Large Retrospective Assessment of Voriconazole Exposure in Patients Treated with Extracorporeal Membrane Oxygenation.

BACKGROUND: Voriconazole is one of the first-line therapies for invasive pulmonary aspergillosis. Drug concentrations might be significantly influenced by the use of extracorporeal membrane oxygenation (ECMO). We aimed to assess the effect of ECMO on voriconazole exposure in a large patient population. METHODS: Critically ill patients from eight centers in four countries treated with voriconazole during ECMO support were included in this retrospective study. Voriconazole concentrations were collected in a period on ECMO and before/after ECMO treatment. Multivariate analyses were performed to evaluate the effect of ECMO on voriconazole exposure and to assess the impact of possible saturation of the circuit's binding sites over time. RESULTS: Sixty-nine patients and 337 samples (190 during and 147 before/after ECMO) were analyzed. Subtherapeutic concentrations (<2 mg/L) were observed in 56% of the samples during ECMO and 39% without ECMO (p = 0.80). The median trough concentration, for a similar daily dose, was 2.4 (1.2-4.7) mg/L under ECMO and 2.5 (1.4-3.9) mg/L without ECMO (p = 0.58). Extensive inter-and intrasubject variability were observed. Neither ECMO nor squared day of ECMO (saturation) were retained as significant covariates on voriconazole exposure. CONCLUSIONS: No significant ECMO-effect was observed on voriconazole exposure. A large proportion of patients had voriconazole subtherapeutic concentrations.